The present invention relates to a syntax analyzing system and, more particularly, to a method and apparatus for analyzing the syntax of a natural language which is applied and inputted to a natural language processing system including a computerized translation system.
A computerized natural language-processing system, such as a machine translation system or computerized translation system, has been recently developed. In such a language processing system, a sentence input to a machine has been automatically analyzed using the syntax of an English system and an output document has been formed and edited in accordance with the analyzed result.
When the syntax analysis of the original sentence input to the machine is performed, the syntactic category of each word forming the input sentence is generally obtained by using a dictionary memory. The dictionary memory stores in advance definitions of numerous words and their syntactic categories, such as nouns, verbs, prepositions and the like. The syntatic analysis of the input sentence is processed based on the syntactic category thus obtained from all of the words included in the input sentence and the rules of grammar.
However, it is generally impossible to register in advance all of the words which may be needed to form a sentence in the dictionary of the machine. When a word unregistered in the dictionary is, accordingly, included in the sentence input to the machine, it cannot determine the syntatic category of the word. Therefore, it becomes impossible to perform the actual syntactic analysis of the input sentence. Consequently, the fact that the processing of such a sentence is interrupted and cannot be continued is a drawback of the conventional natural language-processing system.